Minutes of the HERA Meeting   2.10.2001

1. Schedule: the HERA startup schedule by F.Willeke as of 19.9.2001 was confirmed. The Christmas shutdown starts on Sat, Dec 22, 2001.
2. Bernhard Holzer summarized the progress of the HERA startup during the last 9 days, mainly with the proton machine together with the H1 and ZEUS solenoids:
   • The linear interpolation of the optics from 40 to 300 GeV led to large amplitudes of the beta function around 200 GeV and was given up. An intermediate file still has to be defined, currently the injection optics is used up to 300 GeV.
   • A warm proton magnet QR14 at 60m SR tripped the cooling water pilotherme at 96 degree C, causing beam instability and triggering the quench protection system twice. The optics was changed to run this magnet at slightly lower current.
   • On 1.10.01 2.54 mA protons in 10 bunches where ramped to 920 GeV with hardly any losses and stored with 600h lifetime.
   • The proton optics at 920 GeV did not need corrections for the H1 and ZEUS solenoids and is ready for collisions.
   • For positrons the x-y coupling due to the H1 solenoid could not be fully corrected by the skw quads so far and will be studied further.
3. Hermes:
   • Suffer from high background from e+ beam. Collimators have be closed.
   • The effect of the transverse target magnet on the e+ beam has to be studied. To be scheduled.
4. HERA-B
   • Request a few hours of stable proton beam with injection veto set to study backgrounds and conditions their chambers. To be scheduled.
   • Injection veto to be tested today.
5. ZEUS:
   • Lumi photon detector being commissioned
   • BYZ dipole magnet for lumi pair spectrometer tested: up to -200A no effect on HERA beams
   • Effect of closing the calorimeter on GG and GO field only reproducible within 10%. Holzer intends to install a automatic feedback system for the orbit corrections.
   • Careful beam steering is needed to reduce background seen in the radiation monitor of the silicon microvertex detector.
   • Beam halo muon run requested. Combine with HERA-B stable-p run. To be scheduled.
   • Short stable proton beam run for calorimeter data taking requested. To be scheduled.
6. H1:
   • Low background rates, so far
   • Lumi photon detector being commissioned with beam-gas bremsstrahlung at 12 and 27.5 GeV today.
7. Program:
   • Stable e+ beam: 1 shift today for H1 and ZEUS photon detectors
   • Signals to the e-beam dump will be tested today
   • Study e+ emittance with wire scanner
   • Store and ramp both beams, currents 1-2 mA
   • Attempt collisions: 1p + 3e bunches or 10p + 6e bunches (3 non-colliding)
8. Next meeting: next Tuesday, 9.10.2001, 11:00, Geb 30b, Rm 459

Last modified: Tue Oct 2 18:45:16 MEST 2001